Activated carbon is usually made from bituminous coal or coconut shell. The activation process serves to greatly increase the surface area of the carbon. This is done by exposing the carbon to steam while it is being burned. This forces the carbon to crack, producing an enormous surface area on a relatively small amount of carbon. Carbon can be used as a granular media or it can be compressed into a carbon block cartridge. Contaminants are removed by simple mechanical filtration or by adsorption – meaning the contaminants adhere to the surface of the carbon. Activated carbon has a huge capacity for chlorine removal and a somewhat limited capacity for removing organic chemicals. Some carbon block cartridges are made dense enough to be able to filter out parasites. And some cartridges have other media added to the carbon to enable it to also remove lead.
Benefits: has a very large capacity for the removal of chlorine and is also able to remove organic chemicals; can also be used to remove sediment; very versatile lending to its use in combination with other treatment medias. Is most effective in cold water.
Limitations: removes a relatively small amount of contaminants – about 5% of known contaminants; less effective at chlorine removal in hot water.
Used in combination with deionization by ion exchange, steam distillation, reverse osmosis and with KDF. Is also used by itself.
Products Using Activated Carbon: Carbon Block Tandem, MB Series, and Steam Distillers